Aerial view of Hoover Dam construction site, looking upstream on the Colorado River in Black Canyon. A cooling tower is seen in the foreground. The partially finished dam face is covered with concrete pouring forms and other construction equipment....

Aerial view of the Hoover Dam construction site looking upstream on the Colorado River in Black Canyon. Construction on the power houses in the lower cofferdam is seen in the foreground. The roof of a temporary building is seen in...

Aerial view of the Hoover Dam construction site in Black Canyon. Visible are the spillways, intake towers, dam face, diversion tunnels and construction on the power houses. Temporary buildings are seen in the cofferdam downstream of the dam face. The...

View of the construction of Hoover Dam, looking upstream. Shows concrete forms, high scaling equipment, construction roads, and a train winding along the side of the canyon. The Colorado River is visible above the construction site; various...

View of Hoover Dam site, looking upstream. A railroad winds along the canyon and the Colorado River is visible above the dam site. Buildings and structures, high scaling equipment, and concrete forms are also visible.

Shows Hoover Dam construction from the top of the dam looking down. The power house, valve houses, and lower portals of the diversion tunnels are visible. Various buildings and trucks are also shown. The Colorado River is...

Shows Black Canyon and the Colorado River at the site of the construction of Hoover Dam. Some roads and railroad tracks are visible as well as buildings. Shown also are railroad cars and a temporary suspension bridge.

Shows the downward face of the dam during the latter stages of construction. Concrete pouring forms are visible on the face of the dam and on the power houses. There are several small buildings visible on the floor...

View from on high of Hoover Dam construction, looking upstream. The Colorado River can be seen above the dam. Also shows concrete forms, a train winding along the side of the canyon, high scaling equipment, construction buildings, and...

Overhead view of the construction of Hoover Dam in Black Canyon. Looking upstream, the Colorado River is visible above the dam site. Also shows concrete forms, a train winding along the side of the canyon, and various construction...

Construction site of Hoover Dam in Black Canyon, looking upstream. Above the site is the Colorado River. Shows concrete forms, a train winding along the wall of the canyon, various construction buildings, hoisting machinery, and a cable suspended...

View of Hoover Dam construction site, looking upstream. Above the site is the Colorado River. There are concrete forms, construction buildings, hoisting machinery, and a cable high above the Black Canyon in the picture. There is also...

Construction photo of Hoover Dam in Black Canyon, showing the Colorado River above the dam site. Also shows concrete forms, a train winding along the canyon wall, high scaling and hoisting machinery, various construction buildings and a cable suspended...

Overhead view of the construction of Hoover Dam in Black Canyon with the Colorado River visible above the dam site. In the photo are concrete forms, various construction buildings, a train winding along the side of the canyon, high...

An aerial view of the Colorado River and Black Canyon during the early stages of Hoover Dam construction. The photo was taken from near the top of the dam site, on the Nevada site. It shows a building,...

Construction photo of Hoover Dam. Shows a train winding along the canyon, concrete forms, buildings and structures above the dam, construction roads, high scaling equipment and a cable suspended over the canyon. The Colorado River is visible above...

View taken high above Hoover Dam construction site showing the forms for poruing the concrete. There are trucks, buildings, a railroad, and roads visible. The Colorado River can be seen above the site. Other construction equipment shown includes...

View of the Hoover Dam construction site from high above the canyon. The Colorado River is visible above the dam site. A cable spans the canyon, there is a train winding along the canyon wall, and construction roads...

Aerial photo of the Hoover Dam construction site showing forms for poring concrete. Forms for the power house gallery are visible. A train winds along the canyon wall, there is high scaling equipment on the walls, and the...

Shows Hoover Dam construction from Lookout Point. The intake towers and the Colorado River are visible above the dam. The power houses are being constructed on the floor of the canyon. Also shows trams on cableways stretched...

View of Hoover Dam construction site with the intake towers and Colorado River visible above. The power houses are under construction at the base of the dam. A cable spans the canyon and several construction buidngs are shown....

Shows the Nevada spillway and the face of the dam in the background. Cars are visible on the road across the top of the dam. Some of the intake towers are also visible. Construction equipment, buildings, and...

View from the top of Hoover Dam of construction on the power houses in the lower cofferdam and on the valve houses in the walls of Black Canyon. Temporary buildings and construction equipment are seen on the cofferdam floor. Roof...

View from a distance of Hoover Dam and the canyon. The upstream face, the power houses, and one of the portals to the diversion tunnels can be seen. There are buildings on the cofferdam and part of the...

Shows the construction of Hoover Dam. One of the portals of the diversion tunnels is visible. Dynamite blasting is taking place in the canyon and trucks and various construction buildings are visible on the cofferdam. Also shows some...

"Shows men placing dynamite to flood entrance blocks away from #3 and #4 Arizona side."(inscription on back of photo) The portals to the diversion tunnels are visible. The Colorado River is shown below the portals and buildings and trucks...

"Down stream from Observation Point. Buildings on the right side are water sedimentation plants. Water treated for Boulder City. Left side is Arizona side of River." [hand-written inscription on back of photo] This photo was taken high...

"Upstream from observation point. Note car going down road." [hand-written inscription on back of photo]
Taken from high above the Colorado River, this view shows roads, bridges, buildings and structures, and a car on the side road.

"Looking int.[o] canyon from observation point -- up river bridge is for trucks hauling muck out of upper portals." [hand-written inscription on back of photo]
Taken from an observation point high above Black Canyon, this view shows bridges spanning the...

"Upstream toward lower portals." [hand-written inscription on back of photo] This view shows the Colorado River in Black Canyon during the early stages of the construction of Hoover Dam. A suspension bridge across the river can be...

This postcard shows the construction of Hoover Dam in four different stages. All views were taken from the same point looking upstream. The first image shows Black Canyon and the Colorado River at the very beginning of construction...

Panoramic view of the Hoover Dam construction site. One of the lower portals to a division tunnel can be seen. Buildings, trucks, and the cofferdam are also visible. A portion of the Colorado River is...

Shows a general view of dam construction. Cables, buildings, and roads are visible. Concrete pouring forms can be seen at the bottom of the canyon. A portion of the Colorado River is also visible. The...

"At lower portal mouths on Arizona side of river. Picture taken from Nevada side." (handwritten inscritpion on back of photo) Shows a temporary suspension bridge and several buildings near the lower portals of Hoover Dam. Cables are...